420R (S3) Radiator design issue, regular failures???

[CtrMint]

For a couple reasons I've opened dialogue with Caterham on this.

The main reason is what I feel is the unavoidable scenario which has occurred.  Only after repeated failures have I been able to learn and consider that something is amiss.  I'm not an experienced mechanic, mechanical engineer, and so predicting this failure mode was outside the scope of basically fitting the radiator with the supplied hardware.  My car also seems to have little adjustment and subsequent clearance, I suspect due to the holes in the radiator bracket, either way reaching a conclusion to cut down the hanger was never a consideration.

If the part was say £200 I'd probably chalk it up to experience, but over £600 plus shipping to the IOM, we're something completely different.

[ChrisC]

My hanger is 25mm wide 

[John Vine]

I'm not a welder, but that welding in #1 doesn't look very pretty to me.  I'm wondering whether whoever did it had simply located that tube in the wrong place?

JV

[David aka Blue7]

Looking at the new radiator in the CC store, the location holes are elongated horizontally, can you slacken the mounting bolts in order to slide the radiator to the right so that the bracket will not be touching the hose?  Here is what I am suggesting:

[CtrMint]

I've tried the adjustment, I can't get sufficient travel to clear the inlet.  I think its more height I need so cutting the bottom of the elongated mounting hole so it can be lifted is more likely to be successful.   However, if I do that, I'll need to torque up the bobbins really tight so they support the radiator, which will of course reduce their dampening effect.  I've made this argument to Caterham today, and I'm awaiting a response. The only other option is to add a spacer/insert onto the bolt so that it's raised on the ali edge.  I've bought a load of rubber hardware to trial and error this, but it's going to take time and the real disappointment is missing the Taffia run, two Caterhams off the road.  

I'm also waiting for clarification on the warranty claim.  

Oh interesting I'd been posting on Instagram ( https://www.instagram.com/caterham7diaries/ )all weekend about my prep work for the Taffia, the car looked stunning by the end.  Of course the last image was the failed radiator.  The amount of direct messages I've had as a result from people with similar issues is bloody alarming.  

[SLR No.77]

"However, if I do that, I'll need to torque up the bobbins really tight so they support the radiator, which will of course reduce their dampening effect"

There's something not right here Mark, are you suggesting the bobbin is just a rubber bush?  The bobbins should be a rubber cylinder with a threaded stud bonded onto each side, the studs do not contact each other. However much you tighten the studs it will not be detrimental to the damping provided by the rubber section.

Stu. 

[ScottR400D]

SLR is right, it shouldn't be possible to over tighten and clamp up the rubber bit. 

[David aka Blue7]

Well I think you are taking the best course of action by contacting and complaining to Caterham.  Personally, I don't like their fix and like other comments, I don't like the look of that radiator, which looks cheap and nasty, probably made in Shenzhen and fixings and outlet may not be in the correct positions.  That weld is a disgrace, even a first year apprentice would not produce something as ugly as that, which does not inspire confidence.

Given that you have now had two or three radiator failures, you would probably have a good case to take to the Small Claims Court because they have not been satisfactory quality or fit for purpose but you would need supporting written evidence from someone with expert opinion.  The trouble is that at the end of the day you still have to replace the radiator and all that seems to be available are more crap radiators / or crap brackets.  

IMO Caterham should supply you with a new radiator FOC plus a fix for the problem but I wouldn't hold my breath and the easiest answer at the end of the day is your own fix.  What about making a couple of new brackets or suggesting to CC that they supply modified brackets that would increase the radiator height by say 10mm.  I don't think the bobbin torque would be a problem, the only problem may be clearance with the nose cone.

[CtrMint]

If you take a look at the first post, second image you'll see the bobbin is trapped between the ali bracket and hanger, so has no capacity to flex, and certainly wouldn't if I torqued it up so much that it held the radiator in position should I open up the ali mounts to increase the mounting height.

 

[CtrMint]

honestly, I just can't be arsed.  I've had the patience of a saint while 59K depreciates in the garage tied up in an unused 620R, now need to go through more cr@p.  It's just a joke, one which keeps my peers very much amused.

[SLR No.77]

Mark, regarding the bobbin, I've done some rough mods on your photo below, bare with me, I'm better with engines than I am with techie stuff!

Where I've drawn the red circle you absolutely must have some clearance, this must remain the case when the bobbin is tightened fully which it must be.  If there is not sufficient clearance then maybe add a suitable washer where I've drawn the blue circle?  If fitted correctly the bobbin should appear to be trapped between the ally radiator bracket and chassis hanger.

As far as the chassis bracket is concerned the 90 deg upward bend on the end is the same as has been in place for a lot of years, the small additional bracket is obviously for the fitment of this particular radiator.  The bracket placing upwards pressure and vibration on the hose or radiator entry pipe is likely to be the cause of a radiator failure.  It shouldn't be necessary but as already stated, removing a little material at the contact point might possibly solve the problem.

Stu.

[CtrMint]

Hi Stu,

There's no contact where you marked in red, i.e. the rear of the bolt head.  The contact occurs at the top of the bracket, it hits the inlet pipe on the rad.  There's also contact between the hose and top of the hanger.

Based on the number of people that have messaged me over Instagram, either we're all doing something wrong, or there is a real quality issue here.   Either the design or the rads. 

[TomB]

Wouldn’t a couple of minutes with a grinder and touch up paint on the bracket relieve any pressure on the inlet? 

[ScottR400D]

I wouldn't bet on that being the problem. My money would be on a poorly made radiator from the start. A glance at the welding is a clue. 

Yes, it's a lousy piece of design and engineering but a decent radiator could withstand the bracket touching the hose, IMO. 

[Geoff Brown]

Do we have something occurring of epic proportions that mirrors the TITAN fiasco ?

There may be the need to start a dedicated thread 'viability of the latest aluminium radiators post (insert date here)' then sit back & watch the sh1t hit the fan.........

But it is unlikely that CC will take a jot of notice unless 'politely' threatened by group litigation which I think those with carbon plated Titans should have done. But that is another story.

When the Sigma engined Seven was introduced there was a a big problem with the radiator plastic header & footers leaking/bursting. It took a lot to convince CC that there was indeed a problem to the point that a face to face meet between certain members of the MT at the time & CC finally got the message over.

That was when we had club technical liaison & I was it ! Sadly that post did not last very long as it was deemed to be too much of a hot potato.

[ChrisC]

My only wish would be for CC to not treat road going 420 owners as second class citizens.  Race spec 420 owners get the significantly cheaper option to replace just the coolant radiator, but road spec requires oil and coolant radiator to be replaced at the same time.  The oil cooler is only held onto the coolant radiator with two bolts.

 

[David aka Blue7]

Given that we now have a new relationship with CC, can someone in the MT contact CC with the above evidence and request an official response?  There only appears to be three possible causes of the problem, poor quality radiators, confirmation that they are only designed to last 2k miles or bad design of the adaptor brackets.

I am now of an age that too much stress just increases blood pressure so I would take the "easy" way out and grind / file down the brackets.

[7 wonders of the world]

I was at Alicool yesrterday to collect a fan for my new 60mm rad, speaking to Keith the owner, I mentioned the problems with current 420 rads and he openly talked about why he set up Alicool.

He and 2 others started Radtec, all was well until the other partners wanted to cut cost by buying cores from the far east, Keith objected and during prolonged heated exchanges he decided this wasn't the route for him sold his share and set up his own business.

I mentioned Radtec's claims that using the wrong coolant is causing the failures, he said his rads are fine with any coolant no problem, the problem isn't the coolant but the cheap cores.... he wasn't shocked by the repeated failures at very low mileages either.

If you get no joy with CC might be worth you having a chat with him about making a batch up, I agree that a 2 piece rad / cooler design would be more cost effective for owners to.

There must be more that one failed unit out there to use as a pattern.

[ScottR400D]

I'd buy a rad to the old spec from Radtec, get an oil cooler from Mocal (CC have them in stock as well, £75) and revert to the old specification, which works well and has none of the issues we're seeing here. (Other than the quality of the original rads).

It looks like CC have all the other bits that might be needed in stock too. 

 

[John Vine]

Re #43: Very interesting, Neil -- makes complete sense.  I never did buy the "blame the coolant" notion, and I'd always choose the coolant the engine warrants.

Re #44: I think that's very good advice, provided the rad is of good quality.  That set-up is what I have on my 2008 S3 R400D (except that mine is wet-sump, so I have a sandwich plate on the filter housing and two long oil hoses), and has performed flawlessly for 12 years now. 

APIWATW (from the Assembly Guide):

JV

[ChrisC]

If you choose this route, don't forget to also factory a smaller cooling fan, mounting brackets for the cooling fan and different length oil lines for the oil cooler.  

[ScottR400D]

#45 Once I had the radiator, which leaked from day 1, fixed, mine too has been faultless. 

#46 Yes, of course, a fair point. 

[ChrisC]

From Caterham Parts website, about £742

Radiator, Oil cooler, oil cooler brackets x2 , oil cooler lines x 2, cooling fan, cooling fan brackets x2, bobbins x 4

[StevehS3]

#43 I recently changed my plastic topped, crimp sealed CC rad for Alicool. Having read the BC thread about coolant I raised this with Alicool. As per #43, they informed me to use the correct one for the engine and what is recommended by CC. It appears to be a very solid core and extremely well made but time will tell I suppose. 

[CtrMint]

I'm making appropriate progress with CC, I've now a _chance_ of getting the 420R back on the road in time for the Taffia.  We've had a productive conversation, and while we don't have agreement with respect to the design, I am happy that CC are listening and being very respectful and responsive to my point of view.  I really can't fault them for that.

I've also had a long think about my view of the car, particularly how anal I am with detailing and keeping it mint (check my Instagram).  After considering the potential life span over the next 10 years max, and that i won't sell it with any meaningful value, I've decided to start modifying the car, something I really wanted to avoid, I wanted to ensure it remained 'factory' at all costs.  That view seems to conflict with the practicalities of ownership, and if I'm going get the max from my ownership, I should just accept mods are needed.

Thus I've been up to Screwfix and purchased a new Dremel and various cutting disks, I'm going to carefully cut the corner off the mount where the contact occurs.   I know many of you suggested this, but it just wasn't something I was prepared to do until now.

PS, before someone says it, I do have a grinder, but its a bit of a dangerous weapon in my hands, a dremel is more me ;-)